DCI and dehydration

[lynn jackson]

Hi everyone,

Just a quick question.

Is there any research/evidence of the suggestion that dehydration is a more serious factor in triggering DCI than previously thought?

(I'm asking on the eve of a week's RIB diving in Cornwall...)

[Steve Walker]

Hi everyone,

Just a quick question.

Is there any research/evidence of the suggestion that dehydration is a more serious factor in triggering DCI than previously thought?

(I'm asking on the eve of a week's RIB diving in Cornwall...)


Generally it seems to be considered to be THE most important predisposing factor (excluding rapid ascents, PFO and such like). For a research perspective see the link
HTH
Steve

[pat farrell]

:=Hi everyone,
:=
:=Just a quick question.
:=
:=Is there any research/evidence of the suggestion that dehydration is a more serious factor in triggering DCI than previously thought?
:=
:=(I'm asking on the eve of a week's RIB diving in Cornwall...)
:=

Generally it seems to be considered to be THE most important predisposing factor (excluding rapid ascents, PFO and such like). For a research perspective see the link
HTH
Steve
The theory is that normal hydration must be maintained.
Despite this sound & sensible advice I do not know of a single research paper that proves it.
Keep drinking (not alcohol!)

[pat farrell]

:=Hi everyone,
:=
:=Just a quick question.
:=
:=Is there any research/evidence of the suggestion that dehydration is a more serious factor in triggering DCI than previously thought?
:=
:=(I'm asking on the eve of a week's RIB diving in Cornwall...)
:=

Generally it seems to be considered to be THE most important predisposing factor (excluding rapid ascents, PFO and such like). For a research perspective see the link
HTH
Steve
The theory is that normal hydration must be maintained.
Despite this sound & sensible advice I do not know of a single research paper that proves it.
Keep drinking (not alcohol!)

[PeteM]

Despite this sound & sensible advice I do not know of a single research paper that proves it.

But lets be fair proof is not going to be possible, the most you will ever be able to get to is that dehydration is an important predisposing factor for DCI which has been proved - A quick bit of research has indicated the following as good sources of further information

"Diving Medicine" by Bove and Davis
"Diving and Subaquatic Medicine" by Edmonds, Lowry and Pennefather
"The Physiology and Medicine of Diving" by Saunders

Keep drinking (not alcohol!)

Totally

Pete

[matt]

Is there any research/evidence of the suggestion that dehydration is a more serious factor in triggering DCI than previously thought?

AIUI

Factors influencing a DCI event are surveyed by chamber staff during treatment. Dehydration is very often a factor.
<a href="http://www.diveshow.com.au/Magazine/events.htm" >http://www.diveshow.com.au/Magazine/events.htm</a>

The physiological mechanism that makes dehydration an obvious factor is well understood.

"Dehydration is
dangerous because it reduces the volume
of blood in our bodies - to counteract
this, our system extracts fluid from
other areas, like the skin and muscle
tissues. Less blood flow means a reduced
ability to flush out nitrogen. Dehydrated
divers cannot off-gas as efficiently and
this puts them at a higher risk of DCI!
Another problem with dehydration is the
major role it plays in fatigue; less
blood makes the heart work harder,
hypothermia; less blood volume and
movement means less heat flow, and
possibly, exhaustion - all these
conditions put you at an increased
risk of DCI."
<a href="http://www.picknowl.com.au/homepages/djb/DO" >http://www.picknowl.com.au/homepages/djb/DO</a>'S_AND_DON'TS.htm

ALL the medical experts agree that you should avoid diving when dehydrated and take active steps to maintain hydration before and after diving. Drink lots but avoid diuretics like tea and coffee.
<a href="http://www.show.scot.nhs.uk/sdm/risk.htm#Avoid%20diving%20when%20dehy" >http://www.show.scot.nhs.uk/sdm/risk.htm#Avoid%20diving%20when%20dehy</a>

(I'm asking on the eve of a week's RIB diving in Cornwall...)

Learning to whizz on a small boat is an essential diving skill. Now we have O2 kits on RIBs maybe we should think about adding a bucket and blanket to the safety equipment list.

You can find a light hearted look at what really is a serious subject on the Dive Girl site
<a href="http://www.divegirl.com/wee.html" >http://www.divegirl.com/wee.html</a>

HTH
Matt

[Steve Walker]

:=Is there any research/evidence of the suggestion that dehydration is a more serious factor in triggering DCI than previously thought?

AIUI

Factors influencing a DCI event are surveyed by chamber staff during treatment. Dehydration is very often a factor.
http://www.diveshow.com.au/Magazine/events.htm

The physiological mechanism that makes dehydration an obvious factor is well understood.

"Dehydration is
dangerous because it reduces the volume
of blood in our bodies - to counteract
this, our system extracts fluid from
other areas, like the skin and muscle
tissues. Less blood flow means a reduced
ability to flush out nitrogen. Dehydrated
divers cannot off-gas as efficiently and
this puts them at a higher risk of DCI!
Another problem with dehydration is the
major role it plays in fatigue; less
blood makes the heart work harder,
hypothermia; less blood volume and
movement means less heat flow, and
possibly, exhaustion - all these
conditions put you at an increased
risk of DCI."
http://www.picknowl.com.au/homepages/djb/DO'S_AND_DON'TS.htm

ALL the medical experts agree that you should avoid diving when dehydrated and take active steps to maintain hydration before and after diving. Drink lots but avoid diuretics like tea and coffee.
http://www.show.scot.nhs.uk/sdm/risk.htm#Avoid%20diving%20when%20dehy

:=(I'm asking on the eve of a week's RIB diving in Cornwall...)

Learning to whizz on a small boat is an essential diving skill. Now we have O2 kits on RIBs maybe we should think about adding a bucket and blanket to the safety equipment list.

You can find a light hearted look at what really is a serious subject on the Dive Girl site
http://www.divegirl.com/wee.html

HTH
Matt



Additionally, dehydration will increase the viscosity of the blood resulting in poorer flow and slower gas exchange. One of the many justifications I use for my love of that well documented blood thinning dietary component - garlic ! :)))
Cheers
steve

[Steve Walker]

:=Despite this sound & sensible advice I do not know of a single research paper that proves it.

But lets be fair proof is not going to be possible,

Well it would be if only I could approval for my research proposal, it would also have beneficial effects on the problems of prison overcrowding and truanting schookids :))))
Cheers
Dr Evil ;)

[PeteM]

Additionally, dehydration will increase the viscosity of the blood resulting in poorer flow and slower gas exchange.

Also this is going to get worse over the course of a dive as you breath the dry air (cue RB diver to appear with smug grin) so you will have better gas exchange during the on gassing phase than during the off gassing phase.

No references to hand but I seem to remember the figure of half a litre an hour fluid loss during a dive

Pete

[dave covey]

Is there any research/evidence of the suggestion that dehydration is a more serious factor in triggering DCI than previously thought?

...further to the answers already posted I'd like to emphasise the importance of Oral Rehydrant Salts (ORS) to drinking water in hot climates. The distilling process extracts EVERYTHING from the water, resulting it it passing straight through you without touching the sides & therefore resulting in dehydration and contributing to DCI.

If ORS aren't to hand try adding a teaspoon of salt/sugar, or pop down to the shop for a "gatorade"

HTH

[diverd]

Actually I thought 'Gatorade' and the likes were diuretics?

...'Coffee, tea, soda, electrolyte replacements such as Gatorade, acidic juices, and alcohol are all dehydrators. They deceive you by satisfying your immediate thirst while robbing precious fluids from your system'...

...'The International Sports Medicine Institute recommends you should drink 31cc of water per kilogram of body weight, which means 3.1 litres of water per day for a 100kg person. An athletic person should drink 4.4 litres per day for a 100kg person'... of course if you're in a hot climate, more active than normal, etc, you should quite rightly drink more. Personally, on a typical Red Sea diving holiday, I'm probably drinking 7-9 litres of water per day. Wouldn't you get all your sodium etc requirements from a healthy balanced diet?


regards
diverd

[Iain T]

Wouldn't you get all your sodium etc requirements from a healthy balanced diet?


Not necessarily, I have a few friends serving with the Army in Iraq and there have been quite a few heat injuries despite them drinking plent of water (12 litres/day +). It just flushes all the salts out of your system

Granted, this is an extreme case but diving, particularly in hot climates, can dehydrate far quicker than many realise (as has been noted above) so personally I always like to drink water with a little extra added - even if it is just cordial - to keep the salt levels up.

Dive safe (and fully hydrated!)

Iain

[aquabin]

Additionally, dehydration will increase the viscosity of the blood resulting in poorer flow and slower gas exchange. One of the many justifications I use for my love of that well documented blood thinning dietary component - garlic ! ))
Cheers
steve

Oh now I'm really looking forward to the Farnes!!
Matt

[Steve Walker]

:=Additionally, dehydration will increase the viscosity of the blood resulting in poorer flow and slower gas exchange. One of the many justifications I use for my love of that well documented blood thinning dietary component - garlic ! ))
:=Cheers
:=steve

Oh now I'm really looking forward to the Farnes!!
Matt

don't forget the snoring too :)))))

[aquabin]

:=:=Additionally, dehydration will increase the viscosity of the blood resulting in poorer flow and slower gas exchange. One of the many justifications I use for my love of that well documented blood thinning dietary component - garlic ! ))
:=:=Cheers
:=:=steve
:=
:=Oh now I'm really looking forward to the Farnes!!
:=Matt

don't forget the snoring too ))))

I hadnt ;-(

[Chris Cherrington]

water with a little extra added - even if it is just cordial - to keep the salt levels up.

Mmm... I am new to BSAC (from PADI) my TO assures me that SALT is the paperwork I need to do to be a BSAC diver. Can't see how that affects DCI myself......

[Andy Wade]

water with a little extra added - even if it is just cordial - to keep the salt levels up.

Mmm... I am new to BSAC (from PADI) my TO assures me that SALT is the paperwork I need to do to be a BSAC diver. Can't see how that affects DCI myself......

It helps to keep the relationship cordial...
;-)



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